Ballast scarcity indicator

ABSTRACT

THERE IS PROVIDED A METHOD AND APPARATUS FOR LEVELLING RAILROAD TRACK TO IMPROVE THE PACKING OF BALLAST UNDER THE TIES OF THE TRACK. THE IMPROVEMENT COMPRISES DETERMINING THE WEIGHT OF THE TRACK CARRIED BY THE BALLAST AT A POINT IN THE TRACK AND CONTINUING TO PACK BALLAST UNDER THE TIE AT THAT POINT UNTIL SUBSTANTIALLY ALL THE WEIGHT OF THE TRACK AT THAT POINT IS CARRIED BY THE BALLAST.

Sep 1971 J. K. STEWART BALLAST SCARCITY INDICATOR Filed Aug. 12, 1969LIFT TRACK LEVEL DETECTO R INVENTOR JOHN K. STEWART W "w ATTORNEYSUnited States Patent 3,605,626 BALLAST SCARCITY INDICATOR John KennethStewart, Columbia, S.C., assignor to Tamper, Inc., West Columbia, SC.Filed Aug. 12, 1969, Ser. No. 849,428 Int. Cl. E01b 27/17 US. Cl. 104-121 Claim ABSTRACT OF THE DISCLOSURE There is provided a method andapparatus for levelling railroad track to improve the packing of ballastunder the ties of the track. The improvement comprises determining theweight of the track carried by the ballast at a point in the track andcontinuing to pack ballast under the tie at that point untilsubstantially all the weight of the track at that point is carried bythe ballast.

BACKGROUND OF THE INVENTION This invenion relates to apparatus forlevelling railroad track, that is apparatus for detecting and correctingvertical errors of alignment in railroad track comprising rails securedto ties.

Apparatus for levelling railroad track usually comprises detection meansfor determining the vertical error at a point on the track, means forlifting the track to correct the vertical error and tamping means forpacking ballast underneath the tie at that point to support the trackand to maintain the track at the corrected vertical position. The trackis usually checked for vertical positioning at every tie therealong. Itwill be seen, therefore, that to achieve a reasonable rate of trackcorrection the time occupied in checking the track at each tie should beas short as possible. At the present time track levelling apparatus hasincluded a time delay relay which has allowed the tamping means tooperate for a certain period of time in the packing operation. After thepredetermined period of time the apparatus is moved on to the next pointin the track to be corrected. It has been found that such tracklevelling apparatus does not always result in properly levelled tracks.It has been found that this is due to a scaracity of ballast at some ofthe ties in the track. Thus, when the predetermined period of time foroperation of the tamping means has expired, the tamping means have notbeen able to find suflicient ballast to pack under the tie to take allthe weight of the track so that on release of the track lifting meansthe track has subsided beyond its required vertical position.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide improved track levelling apparatus and an improved method oflevelling railroad tracks.

It is a further object of the invention to provide an apparatus and amethod which determines that a tie at a particular point at which thetrack is being levelled is fully supported by ballast at the end of thelevelling operation at that point.

According to the invention, there is provided in a method of levellingrailroad track such as described above the improvement comprisingdetermining the weight of the track carried by the ballast at aparticular point being levelled and continuing to pack ballast under thetie at that point until substantially all the weight of the track atthat point is carried by the ballast.

The invention provides apparatus for levelling railroad track includingthe combination of detection means for determining a vertical error inthe track at a point therein, lifting means for the track at that point,said lifting means being controlled by the detection means to lift thetrack 3,605,626 Patented Sept. 20, 1971 sufficiently to correct thevertical error, tamping means for packing the ballast under a tie atthat point to support the track in its correct vertical position, andcontrol means associated with the [lifting means for determining theweight of the track carried by ballast under the tie.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention willnow be described by way of example in conjunction with the accompanyingdrawings which is a somewhat diagrammatic representation of part of atrack levelling apparatus showing the features of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawing showsdiagrammatically one side only of track levelling apparatus having amain frame 1 which carries wheels 2 running on a track comprising rails3 (only one of which is shown) secured to ties 4 (only one of which isshown) which rest on a bed of ballast 5.

Secured to the forward end of the frame 1 of the apparatus is tampingmeans shown generally at 6 and comprising a frame 7 secured to the frame1 and having tamping heads 8 mounted thereon for movement verticallywith respect to the track and for movement towards and away from a tie 4in a manner generally known. Similarly, the lifting means shown in thedrawings are generally known. Such lifting means comprise a hydraulicpiston and cylinder assembly 9 having a foot 10 connected to a pistonrod 11, the foot 10 being adapted to extend to the ballast 5. Thecylinder 12 of the assembly 9 is connected to the frame 1. Alsoconnected to the frame 1 is a lifting hook 13 which has claws 14 forgripping on either side of a rail 3. As is known in the art, onpressurization of the cylinder assembly 9 the foot 10 can extend intocontact with the ballast 5 and the hook 13. grips a rail. Continuedpressurization of the assembly 9 causes the piston rod 11 to extendlfting the frame 1 and the rail 3-.

The control apparatus is of a conventional type comprising a track leveldetector 15 which may be of the wire controlled type or of the lightbeam controlled type, a lift control 16 which controls the flow ofpressurized hydraulic fluid along a conduit 17 to the assembly 9 bymeans of a valve 17a to lift the rail 3 as required by the detector 15,and a tamping means control 18 which is brought into operation to havethe tamping heads 8 pack ballast under a tie 4 when the track leveldetector 15 has determined that the track has been lifted the requiredamount.

In accordance with the present embodiment of the invention, a pressuretransduecr 19 is located in the cylinder 12 of the assembly 9. Thetransducer 19 is connected to a relay 20 which provides overridingcontrol on the tamping means. The transducer relay contacts aremaintained in a closed position by any pressure over a predeterminedminimum pressure in the cylinder 12. When the contacts in relay 20 areclosed, an actuation signal is given to the tamping control 18. Thissignal from the relay 20 of course only actuates the tamping heads afterthe initial signal has been given by the lift control 16.

In operation, the apparatus is moved along the track to a point at whichthe determination of track level is to take place. The apparatus isstopped and the track level detector 15 is actuated to determine whetherthere are errors in the track level at that point by reference to adatum which may be in the form of a reference beam or a wire. Should thetrack level detector determine that there is a vertical error in thetrack, it actuates the lift control 16 to place the foot 10 of thehydraulic cylinder assembly 9 on the ballast 5 and to place the grippingmeans 14 of the lifting book 13 about the rail 3. Increased pressure isapplied to the cylinder 12 to lift the rail 3 and the apparatus thereonuntil the track level detector 15 indicates that the rail is at thecorrect vertical position. The hydraulic line 27 to the cylinder 12 isthen closed and the tamping control 18 actuated to operate the tampingheads 8 to pack ballast under the tie 4. The pressure in the cylinder 12has meanwhile acted upon the transducer 19 to close the contacts in thetransducer relay 20 to pass a signal to the tamping control 18. Thissignal maintains the tamping heads in operation and is in effect as longas the transducer relay contacts are closed. As ballast is packed underthe tie, the ballast takes an increasing portion of the weight of thetie, then the cont-acts of the relay 20- will is removed from the pistonand cylinder assembly 9. When substantially the whole of the weight ofthe track is taken by the tie 4, the pressure in the cylinder assembly 9reduces to below the aforesaid predetermnied value opening the contactsof the relay 20 deactivating the tamping control 1'8 and stopping theoperation of the tamping heads 8. Should there be insufiicient ballastin the proximity of the tie 4 to be transferred under the tie 4 to takethe weight of the tie, then the contacts of the relay 20 will remainclosed. In this event, it will become apparent, by continued operationof the tamping heads, to the operator that there is an insufliciency ofballast and he can then remedy the situation by supplying additionalballast.

When the pressure in the cylinder 12 has reduced to substantially zeroand the contacts of the relay 20 have opened, the rail 3 is at itscorrect position and will not subside on release of the lifting means.When the contacts of the relay 20 open, the levelling cycle isterminated 4, and the apparatus is moved on to the next pointon thetrack at which levelling is to take place.

What I claim as my invention is:

1. In apparatus for levelling railroad track, the combination of:detection means for determining a vertical error in the track at a pointtherein; a hydraulic piston and cylinder assembly for lifting the trackat that point, said lifting assembly being controlled by the detectionmeans to lift the track sufliciently to correct the vertical error;tarnping means for packing ballast under a tie at that point to supportthe track in its correct vertical position, and control means includinga pressure transducer for determining when the said tie is taking theweight of the track by determining a reduction in pressure in saidassembly and said control means being 'operatively connected to saidtamping means to cause a repeat operation of the tamping means untilsaid transducer determines that the pressure in said assembly is below apredetermined value.

References Cited UNITED STATES PATENTS 3,177,813 4/1965 Stewart 104-l23,459,135 8/1969 Stewart l04-7 ARTHUR L. LA POINT, Primary Examiner R.A. BERTSCH, Assistant Examiner

